Resource reservation method and apparatus

Abstract

This application provides a resource reservation method and an apparatus. The method includes: receiving, by a node, a first message, where the first message carries a bandwidth value r 1 of a resource requested to be reserved and a quantity Q 1 of cycles occupied by the resource, the node maintains resource reservation states in K cycles, K is a positive integer, and Q 1 is less than or equal to K; and updating, by the node, resource reservation states in Q 1 of the K cycles based on the bandwidth value r 1 and the quantity Q 1 . The node maintains the resource reservation states at a granularity of cycles. Therefore, the resource reservation states that need to be maintained by the node do not depend on a quantity of data flows processed by the node, and a performance requirement of a resource reservation for the node can be lowered.

What is claimed is: 
     
         1 . A resource reservation method, comprising:
 receiving, by a node, a first message, wherein the first message carries a bandwidth value r 1  of a resource requested to be reserved and a quantity Q 1  of cycles occupied by the resource, the node maintains resource reservation states in K cycles, K is a positive integer, and Q 1  is less than or equal to K; and   updating, by the node, resource reservation states in Q 1  of the K cycles based on the bandwidth value r 1  and the quantity Q 1 .   
     
     
         2 . The method according to  claim 1 , wherein a resource reservation state in each of the K cycles is determined based on a total bandwidth of resources that have been reserved by the node in each cycle. 
     
     
         3 . The method according to  claim 2 , wherein the resource reservation state in each of the K cycles is the total bandwidth of the resources that have been reserved by the node in each cycle; and
 the updating, by the node, resource reservation states in Q 1  of the K cycles based on the bandwidth value r 1  and the quantity Q 1  comprises:   adding, by the node, the bandwidth value r 1  to a bandwidth value corresponding to a resource reservation state in each of the Q 1  cycles.   
     
     
         4 . The method according to  claim 2 , wherein the resource reservation state in each of the K cycles is a total bandwidth of remaining available resources of the node in each cycle; and
 the updating, by the node, resource reservation states in Q 1  of the K cycles based on the bandwidth value r 1  and the quantity Q 1  comprises:   subtracting, by the node, the bandwidth value r 1  from a bandwidth value corresponding to a resource reservation state in each of the Q 1  cycles.   
     
     
         5 . The method according to  claim 1 , wherein the updating, by the node, resource reservation states in Q 1  of the K cycles based on the bandwidth value r 1  and the quantity Q 1  comprises:
 updating, by the node based on the bandwidth value r 1  and the quantity Q 1 , resource reservation states in Q 1  cycles starting from a first start cycle in the K cycles, wherein the first start cycle is a cycle within which a start moment at which the node makes a resource reservation based on the first message falls. 
 
     
     
         6 . The method according to  claim 5 , wherein the first start cycle is a current cycle when the node receives the first message. 
     
     
         7 . The method according to  claim 5 , wherein the first message further carries information about the first start cycle. 
     
     
         8 . The method according to  claim 5 , wherein the first message carries cookie cookie information, and the cookie information comprises: the bandwidth value r 1 , the quantity Q 1 , the first start cycle, and a sending interface of the node. 
     
     
         9 . The method according to  claim 7 , wherein the method further comprises:
 receiving, by the node, a second message, wherein the second message and the first message are associated with a same data flow, the second message carries information about a bandwidth value r 2  of a resource requested to be reserved again and information about a quantity Q 2  of cycles occupied by the resource, and Q 2  is less than or equal to K; and   updating, by the node based on the bandwidth value r 2  and the quantity Q 2 , resource reservation states in Q 2  cycles starting from a second start cycle in the K cycles, wherein the second start cycle is the (Q 1 ) th  cycle after the first start cycle.   
     
     
         10 . The method according to  claim 1 , wherein the updating, by the node, resource reservation states in Q 1  of the K cycles based on the bandwidth value r 1  and the quantity Q 1  comprises:
 determining, by the node based on the bandwidth value r 1 , the quantity Q 1 , and a resource reservation state of the node in the current cycle, whether the node supports a resource reservation; and 
 when it is determined that the node supports a resource reservation, updating the resource reservation states in the Q 1  of the K cycles. 
 
     
     
         11 . The method according to  claim 10 , wherein the determining, by the node based on the bandwidth value r 1 , the quantity Q 1 , and a resource reservation state of the node in the current cycle, whether the node supports a resource reservation comprises:
 when a bandwidth value of a remaining available resource of the node in the current cycle is greater than or equal to the bandwidth value r 1 , determining that the node supports a resource reservation; or   when a bandwidth value of a remaining available resource of the node in the current cycle is less than the bandwidth value r 1 , determining that the node does not support a resource reservation.   
     
     
         12 . The method according to  claim 1 , wherein the first message is a reservation Resv message, and the Resv message comes from an egress edge node of a transmission path of a data flow for which a resource reservation is requested. 
     
     
         13 . The method according to  claim 12 , wherein before the node receives the Resv message, the method further comprises:
 receiving, by the node, a path path message from an ingress edge node of the transmission path; and   updating, by the node, the path message, wherein the updated path message further carries the cookie information of the node, and the cookie information of the node comprises: the bandwidth value r 1 , the quantity Q 1 , the first start cycle, and the sending interface of the node, wherein the first start cycle is the cycle within which the start moment at which the node makes a resource reservation falls.   
     
     
         14 . A communications apparatus, comprising:
 a transceiver unit, configured to receive a first message, wherein the first message carries a bandwidth value r 1  of a resource requested to be reserved and a quantity Q 1  of cycles occupied by the resource, the node maintains resource reservation states in K cycles, K is a positive integer, and Q 1  is less than or equal to K; and   a processing unit, configured to update resource reservation states in Q 1  of the K cycles based on the bandwidth value r 1  and the quantity Q 1 .   
     
     
         15 . The communications apparatus according to  claim 14 , wherein a resource reservation state in each of the K cycles is determined based on a total bandwidth of resources that have been reserved by the node in each cycle. 
     
     
         16 . The communications apparatus according to  claim 15 , wherein the resource reservation state in each of the K cycles is the total bandwidth of the resources that have been reserved by the node in each cycle; and
 the processing unit is specifically configured to add the bandwidth value r 1  to a bandwidth value corresponding to a resource reservation state in each of the Q 1  cycles.   
     
     
         17 . The communications apparatus according to  claim 15 , wherein the resource reservation state in each of the K cycles is a total bandwidth of remaining available resources of the node in each cycle; and
 the processing unit is specifically configured to subtract the bandwidth value r 1  from a bandwidth value corresponding to a resource reservation state in each of the Q 1  cycles.   
     
     
         18 . The communications apparatus according to  claim 14 , wherein the processing unit is specifically configured to update, based on the bandwidth value r 1  and the quantity Q 1 , resource reservation states in Q 1  cycles starting from a first start cycle in the K cycles, wherein the first start cycle is a cycle within which a start moment at which the node makes a resource reservation based on the first message falls. 
     
     
         19 . The communications apparatus according to  claim 18 , wherein the first start cycle is a current cycle when the node receives the first message. 
     
     
         20 . The communications apparatus according to  claim 18 , wherein the first message further carries information about the first start cycle.